Turnbull stressed Australia enjoyed "very good relations" with China, but described Beijing's South China Sea foreign policy as "counter-productive".

"You would think that what China would seek to achieve is to create a sufficient feeling of trust and confidence among its neighbours that they no longer felt the need to have the US fleet and a strong US presence in the western Pacific.

"Now what the island construction and all of the activity in the South China Sea has done has resulted in the smaller countries surrounding that area turning to the United States even more than they did before."

Turnbull gave as an example Vietnam, which despite "a very different history with the United States, is now seeking its support".

Taiwan, Vietnam, the Philippines, Malaysia and Brunei all have rival claims to the waters, which incorporate strategic shipping lanes and may hold oil and gas deposits.

The Pentagon has warned that China's activities are changing the status quo and has weighed sending warships and surveillance aircraft within 12 nautical miles -- the normal territorial zone around natural land -- of the new artificial islands.

Beijing said in August it had finished the land reclamation work but a Washington think-tank last week said China may be building its third airstrip in the area.

China insists its facilities are intended for civilian as well as military purposes and has stressed it is committed to maintaining peace and assuring freedom of navigation in the area.